The invention relates to a device for sealing a tube, in particular a lance shaft, in an opening which is located in a component, in particular in a nozzle connected to a cover of a reactor pressure vessel, a pressure element being in operative connection with the tube for pressing the tube against the component.
For various applications, it is conventional practice to connect a tube to a component in a liquid-tight manner or even in a gas-tight manner, the component being part of a vessel. Such a vessel may be the reactor pressure vessel of a nuclear power station, and the component may be a nozzle that is connected to the cover of the reactor pressure vessel. The tube may be a lance shaft, through which, for example, measuring probes or cables may be passed. Especially when used in a nuclear power station, it is necessary for the tube, in particular the lance shaft, to be tightly connected to the component.
On the other hand, during an inspection in the nuclear power station, it is necessary for the tight connection between the lance shaft and the cover nozzle to be opened and to be closed again after a thorough examination. Proper closure requires the action of the pressure element to be checked.
It has hitherto been conventional practice to use pressing screws as pressure elements, the fitting of which pressing screws is complicated and can only be carried out by personnel. In order to check a pressure element, mechanical caliper gauges had to be used manually, which in a nuclear power station requires the use of personnel with protective clothing and is time-consuming.
It is accordingly an object of the invention to provide a device for sealing a tube, in particular a lance shaft which overcomes the above-mentioned disadvantages of the prior art devices of this general type, which device, in particular during a check, does not need the use of personnel or only needs the use of minimum personnel at the seal itself and nonetheless can be manipulated quickly and reliably.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for sealing a tube in an opening located in a component, including a hydraulically driven pressure element being in operative connection with the tube for pressing the tube against the component. In particular, the tube can be a lance shaft in a nozzle connected to a cover of a reactor pressure vessel.
This object is achieved according to the invention in that the pressure element can be driven hydraulically.
This achieves the advantage that the pressure element can be moved in a remote-controlled manner. By a hydraulic medium that is fed via a pipeline and is a liquid as a rule, the pressure element is moved without a person having to work directly at the pressure element.
The pressure element contains, for example, a disk spring, which is disposed between the component and a pressure part producing a force. This pressure part may be a hydraulic cylinder. The disk spring produces a preloading force, which helps to form a tight connection.
If, after an inspection, the tube, in particular the lance shaft, has been disposed again in the component, in particular in the nozzle of the cover of the reactor pressure vessel, the preloading force of the disk spring also has to be reset and checked. With the device according to the invention, this may advantageously be done hydraulically and thus in a remote-controlled manner via a hydraulic line.
To measure the preloading force of the disk spring, a pressure gauge is connected, for example, to a hydraulic line of the pressure element. The pressure measured there of the medium in the hydraulic line allows the preloading force of the disk spring to be inferred directly. The preloading force can be varied by simple adaptation of the pressure, for example by a pump.
The invention achieves in particular the advantage that the sealing and even, if need be, the checking and setting of a preloading force of the disk springs can be effected quickly and reliably via a hydraulic line. Advantageously, it is not necessary to use personnel with substantial protective clothing directly at the component, which may be part of a reactor pressure vessel of a nuclear power station.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for sealing a tube, in particular a lance shaft, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.